In prior art systems, documents, such as human interface descriptions, typically are described with a standardized document description language (SDL). The term “human interface” as used herein after, describes any kind of application interface for a human to interact with application programs that run on a computer. Examples for human interfaces are graphical user interfaces (GUI) or voice user interfaces (VUI).
Typically, the SDL is an “Extensible Markup Language” (XML) based language that provides a set of layout controls, wherein a layout control comprises description instructions that describe a specific layout element (LE). A transformer program, comprising transformation rules, transforms the layout element into a browser compliant description. In a SDL, typical layout elements are “row,” “cell,” “table,” “grid,” etc. Such layout elements can be reused in any context of any application.
A browser, as used herein after, is a computer program that “renders” a document which is written in a markup language, such as “Hyper Text Markup Language” (HTML), “Wireless Markup Language” (WML) or “Voice Extensible Markup Language” (VXML), into a visual or audio presentation of this document. A browser can be device specific. For example, a browser that renders a HTML document on a personal computer screen differs from a browser that renders a WML document on a wireless application protocol (WAP) cell phone display.
The browser compliant description can be rendered by a conventional browser into corresponding visual or audio layout elements on an output device of a computer.
In the XForms 1.0 specification (8 Jun. 2001) of the World Wide Web Consortium (W3C), the assumption is made that data information and layout information are separated from the beginning when a new document is created. This requires the exact knowledge of the data model that is used in an application using the new document. Data model, as used herein after, corresponds to a data description of data that are used (displayed, played, captured, etc.) by the document. However, there are applications where the data model of the application is not known when the document design starts. For example, when an application programmer builds a survey application, typically, the information that is to be captured through a survey form (questionnaire) is defined while developing the survey document. Input fields are added to the form as they are defined during the design process. In general, no data model exists that describes the corresponding data (e.g. dependencies between data, such as questions in a group of questions).